Abstract
Two tomato morphotypes (cvs. Favorita, Organza and Azarro) of different fruit size were grown during 2005-2006 on a rockwool substrate under greenhouse conditions. Leaf area index (LAI), solar radiation absorption coefficient (TAO) and leaf area duration (LAD) were determined. Tested tomato cultivars proved different yielding strategies expressed by dissimilar values of the measured and calculated physiological indices (LAI, LAD, TAO and the canopy yielding efficiency). Cv. Organza showed the highest canopy yielding efficiency, cv. Azarro showed a negative dependence between LAD and yield, while cv. Favorita canopy architecture allowed to achieve better penetration of light energy to lower canopy layers and showed better tolerance of this cultivar to thermal stress.